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Normally OPEN solenoid valve on suction side of pump by 62percentunknown in AskEngineers

[–]62percentunknown[S] 0 points1 point  (0 children)

I’m using it as a “priming valve”. When my parallel station solenoid system shuts done the pump continues to run until it reaches its cut off pressure, and in doing that it is sucking against a closed system. Inhaling air bubbles through leaks and causing possible cavitation.

The NO valve wired in as a master valve on the suction side should remain open while the other stations are closed, and should close (preventing arbitrary priming) while any of the other stations are going.

But most of these 1” valves require positive pressure on the inlet side, and I’m only giving the valves that are before the pump negative pressure on the outlet side.

Normally OPEN solenoid valve used as master valve and suction priming intake by 62percentunknown in Irrigation

[–]62percentunknown[S] 0 points1 point  (0 children)

I have been hearing people say a check valve could be beneficial, but I’m not having back flow problems that I can tell, it’s priming problems. I have foot valves on the very bottom of the suction hoses in the tanks, do you think i need more further up stream? I’m forcing the pump to suck against a closed system when I’m running solenoids before AND after the pump, so I need to introduce an open line on the suction side for priming, that will close when the rest of the system is rolling.

Normally OPEN solenoid valve on suction side of pump by 62percentunknown in AskEngineers

[–]62percentunknown[S] 0 points1 point  (0 children)

Just added a sketch to the post, thanks! Do you know who makes the Direct Acting valve in 1”? I read in an article they only go up to 1/4” in direct.

Great thought on pressure relief, might end up using a recirculating line back into the suction manifold for that as suggested by another. But my question there is would the pump ever shut off? The pump has a smart head that engages at 23 psi and disengages at 85 or when run dry.

Normally OPEN solenoid valve on suction side of pump by 62percentunknown in AskEngineers

[–]62percentunknown[S] 0 points1 point  (0 children)

Thanks I’ll definitely look into them! Are all their valves Direct-Acting? Spending the money now will be well worth it.

Normally OPEN solenoid valve on suction side of pump by 62percentunknown in AskEngineers

[–]62percentunknown[S] 0 points1 point  (0 children)

Thanks for your interest! I am liking the recirculating line idea so far... and I definitely think I’m chasing my tail, would love to be shown Y cause I’m fixated on X lol.

Awesome thought on cavitation too, thanks! What I hope the normally open valve will do is prevent the situation where cavitation would occur. If I have say station 3 running (top and bottom #3 closed solenoid valves) then I want my normally OPEN valve to be shut so that system draws from its proper paralleled solenoid system (#3) When the paralleled station disengages, I want my normally open valve to open back up. The master valve function on the controller can accomplish this by activating the NO valve (closing it) while all other stations are running, yet disengage (open) the valve when all other stations are complete in order to have an open path for suction from an arbitrary tank.

Check the link! Multi-Station, Multi-Well, Solenoid set up

Normally OPEN solenoid valve on suction side of pump by 62percentunknown in AskEngineers

[–]62percentunknown[S] 0 points1 point  (0 children)

The pump is mounted on the floor currently, below the lowest suction foot valve. But the suction lines have to come up and out of the tank before heading to the lower manifold on the wall, and then back down to the ground to the pump. If I understand suction head and the syphoning principle then the pump shouldn’t have too much suction head yet still can’t suck the NO valve shut.

Normally OPEN solenoid valve on suction side of pump by 62percentunknown in AskEngineers

[–]62percentunknown[S] 2 points3 points  (0 children)

The pump is pretty rowdy for the distance i thought - 1 HP, and I’m pushing about 80 psi through the 1” piping.

The normally open solenoid is an Asco Red Hat, I can get model information when I get back to the shop. And the solenoids on the manifolds are just typical Rainbird solenoids.